Master key disk lock



May 31 1932.

Filed Dec. 20, 1928 2 Sheets-Sheet 1 III? II] l Jill May 31, 1932. MvFALK 1,860,708

MASTER KEY DISK LOCK Filed Dec. 20, 1928 2 Sheets-Sheet 2 Z4 Z2 75 iiPatented May 31, 1932 PATENT OFFICE.

MORRIS OF FITGHBURG; MASSACHUSETTS MASTER KEY DISK LOCK Application 'meaDecember 20, 1928. Serial No. 327,437.

This invention relates to a cylinder lock of the disk type, and thechief object is to enable the manufacturer or anyone who is familiarwith lock work, to set the combinations in a number of cylinder lockswhere each and every lock is of a different key change and soconstructed that one master key will open them all. Heretofore oncylinder locks, this could be accomplished only on pin tumbler typelocks by splitting the pins, whereby one section of the pins woul lineup with the use ofthe regular key, and the other section with the use ofthe master key. On the disk type lock, owing to its construction, thedisks cannot be split.

Another ob'ect of the invention is to provide these di in such form thatthey will not fall out when the cylinder is removed and yet cannot betampered with in any'ordinar way.

Re erence is to be had to the accompanying drawings in'which l Fig. 1 isa side view of a lock constructed in accordance with this invention,with the case in section, showing it in locked condition;

Fig. 2 is a longitudinal sectional view with the ordinary key inposition unlocking the cylinder; 1

Fig. 3 is a transverse sectional view on theline 33 of Fig. 2;

Fi 4 is a longitudinal sectional viewshowmg the lock unlocked by themaster key; Fig. 5 is a transverse sectional view on the line 55 of Fig.4; v

Fig. 6 is a view of a set of sixteen disks',.and

Fig. 7 is a view of a disk showing how the}. invention can be used forcooperation with a grand master key as well as a master key.

I have designed a special disk, dividing the section of the disk thatcomes in contact with the key in two parts, using different'steps orcuts on one half of the disk to give the vari- I, one changes on thelock when used with the regular key, and on the other half-to be used sothe disks on the master key side shall have the same combination in anynumber of locks, and on the other side, or the regular key side,

each cylinder will have a different combination. Thus a key of onecylinder will not open the others, while on the opposite side ,the disksare set up with'one particular combination and the master ,key cut tothis particular combination will open all the various locks set thisway. For example, when a lock is set up to a certain combination,certain numbers are used to go by. The disks are generally out tocorrespond to these particular numbers, and to make each lock adifferent combination, we change one or more numbers on the disks. Ifthe numbers-remain the same, it is understood that the locks will be thesame and. will interchang, one with another. What is done in this caseis. to have the numbers changed in every lock on the regular key sideand on the master side to have the numbers or combinations alike on asmany locks as necessary for any particular job.

Example-Diskset-ups Regular key side Master key side 23232 14324 1212314324 12234 14324 32432 14324 31442 14324 43321 14324 While thesecombinations canbe set to a number of locks on the master side alike, it

can also be changed at any time to another number on this particular job(or building) or 'OIlFaIlOtheI job, so the master key and locks can bechanged for each job where a number of diflerent cylinder lgcks arewant- 9 ed, so that each one of the regular keys will operate only onelock, and the master key will operate them all. Heretofore the use ofthe disk or wafer type of lock has been limited to a great extent toautomobiles, or other units where individual changes were suflicient andmaster keyed locks not necessary. By being able to master this type oflock, its .uses 'are now unlimited, and it can be used for front door inbuilding, apartment offices, padlocks, trunks, and various other uses.

Another useful improvement on this type of cylinder disk lock is this:Heretofore, when this type plug was removed from the cylinder and thekey withdrawn, the disks would all drop out, with the result that manydisks would get lost or the combination become changed so as to make thelock useless, unless it was put together again by someone Who isfamiliar with this type of work. I have, therefore, designed a specialcylinder plug and special disks which make it impossible for the disk todrop out when the plug is removed from the shell, and the key withdrawn.

The'invention is shown as applied to a plug 12 of the ordinary kindslotted in the usual way. It is provided with a series of disks 24 inslots in the plug, each disk being pressed outwardly by a spring 27.

In this case each disk is of a general rectangular shape, as usual, buthas a projec 31, in the slot in the plug 12 when the spring forces thedisk out so as to hold the disk in the position shown in Fig. 1. Onaccount of the projection 29 it is possible to move the disk carefullyand get it out of the plug in spite of this projection when the plug isout of the lock. However, such procedure requires some pressure andmovement of the parts so that the disks cannot get out of placeaccidentally. Therefore these plugs can be assembled with the disks inthem and shipped with no external means for holding the disks inposition. This gives the automobile manufacturer the opportunity ofhaving these plugs assembled with no chance of losing time by the diskscoming out and solves a very important problem for him. Also, as

- the disk out and it cannot be doneby ordinary picks and the like. vWhen assembled in the lock, said disks 24 requires a slight pressure topush the disk into the slot until the projection 29 ets beyond theundercut 31 in said plug, t en the disk will start working freely again,andithe projection, coming up against the shoulder 31 of the undercut inthe plug, stops the disk from coming out in the usual handling when thekey is removed. However, said disk can be removed at all times byapplying pressure on the back of said disk to put it through the tion 29on one side which engages a shoulder the projection 29 is rigid, it isnot easy to get slot through the upper part of said plug. By thisconstruction the disk is not weakened by any slit in the periphery.

The principal feature of the invention invol ves the employment of thistype of lock for use with a master key. For that purpose I have providedin addition to the ordinary key 30 a master key 31. The two keys lookabout alike and the two handles are exactly alike except that one may bemarked to indicate that it is a master key, but the shaft of theordinary key is arranged so that the cam projections which operate thedisks are in a straight line along the left-hand side as shown in Fig.3. But in Fig. 5 the master key is shown in position, and in this casethe cam portions are on the right-hand side. In this way the two keyswhen put into the same hole at different times will engage the disks indifferent areas.

I take advantage of this fact to operate these locks ordinarily by thekey 30 through surfaees 33 on one side of the bottom of each disk. Thesesurfaces are at different distances from the top of the slot throu h thedisk, as appears in Fig. 6, to provide or the different combinations.Also in the bottom and at different distances from the top of the slotare another series of surfaces 34 on the right-hand side of each diskdesigned to cooperate with the master key and provide for unlocking anynumber of locks which are arranged for that particular master key.

In Fig. 6 is shown a set of sixteen of these disks each set of fourarranged horizontally,

being for the same look. It will be seen that the first lock is unlockedby an ordinal y key having the numbers 1-111 and by a mas- -ter keyhaving the numbers 1-2,34. The

next horizontal set is unlocked by an ordinary key having the numbers2-222, but by the same master key, and the othertwo sets are arrangedsimilarly. In this way all four of these locks will be capable of beingunlocked by the same master key, but each one has to have a differentordinary key.

In this way without material'extra expense disk locks of this charactercan be set up to be used with two sets of keys, the ordinary and themaster key.

In Fig. 7, I have shown. the disk wider somewhat and three areas on it,the areas 31 and 32 as before for an ordinary key and a fixed mysignature.

. MORRIS FALK.

